The main purpose of the proposed research is to determine the detailed mechanism by which O2 oxidoreductases catalyze reactions of molecular oxygen. Since many O2 oxidoreductases are involved in defects of metabolism it is hoped that a greater understanding of their mechanism will aid in the control or alleviation of such metabolic diseases. One enzyme receiving special attention is kidney inositol oxygenase, an enzyme known to be deficient in diabetes. Since there is some question concerning the metabolic pathway of glucuronic acid (the product of the above enzymic reaction) metabolism, some experiments to clarify this pathway are also being performed. In addition, some oxidase catalyzed reactions, including that catalyzed by diamine oxidase, are being studied, and some non-enzymic models for various biological redox reactions are being investigated. The methods to be used are those which have been proved so successful in arriving at a greater understanding of non-redox enzymic reactions. They will include: kinetic methods, isotope tracer studies, used of inactivators and modified substrate molecules, EPR techniques, etc.